The present invention relates to the field of controlling access to pipes, pressure vessels, and tanks.
Tanks, pressure vessels, and pipes are employed in many manufacturing and distribution facilities. Inevitably, containers of this kind require maintenance or repair and must be disabled temporarily and opened for the purpose of access. Unfortunately, the basis of this nature left in an open condition constitute a danger to living beings which may inadvertently enter the tank and be trapped or asphyxiated by gaseous material found in the tanks. Normally, containers such as tanks possess an entrance structure, commonly referred to as a manway. Since the venting of a container is important prior to maintenance and repair work being performed on the container, the manway must be left open. Such competing objectives still pose a danger to living entities in the vicinity of the container.
In the past, covers have been devised for vessels and containers. For example, U.S. Pat. No. 5,017,044 describes a fibrous reinforced tank having a cover which is held on by a flange arrangement.
U.S. Pat. Nos. 412,190, 1,222,035, 4,011,607, and 4,771,909 describe protective covers for tubs and flasks which completely seal the opening to the same.
U.S. Pat. No. 5,547,102 shows a manway bulge restrictor in which a tension bearing structure prevents distortion of a cylindrical plastic container.
U.S. Pat. No. 5,715,965 describes a hatch plug composed of rubber which is inserted in an opening to a tank and includes an open end and a closed end to radially compress the plug around the manhole for sealing purposes.
A cover for an entrance to a container such as a tank manway which is capable of monitoring the manway in conjunction with an analytical probe would be a notable advance in the field of industrial containers.
In accordance with the present invention a novel and useful device for monitoring a container entrance structure is herein provided.
The device of the present invention utilizes a shield which is capable of covering the entrance structure to a container such as a tank manway. The shield includes a plurality of passages through the same to permit the passage of gas to and from the interior of the container. In this way, the shield not only prevents entering of the tank through the manway, but allows ventilation of the tank prior to and during the maintenance and repair of the same. In this regard, the shield may be formed of a mesh material and include a first side, which is exterior to container, and a second side, facing the interior of the container at the manway.
Fastening means is also found in the present invention for holding the shield to the periphery of the entrance structure of the container. Such fastening means may take the form of an elastic line fixed to the edge of the shield. Also, the fastening means may take the form of a cinchable line or tie-down. In any case, the shield may be fastened or loosened for removal from the entrance structure of the container in a simple and easy manner.
The invention also possess support means for positioning an elongated probe through the shield from the first side to the second side of the same. The probe is supported by the shield so that it may be easily viewed to obtain data from the same. The shield may be constructed with a reinforcement surrounding an opening to permit the probe to slide back and forth relative to the shield without damaging the same.
Moreover, the shield first side at the exterior of the container may include a placard with indicia providing cautionary advise to persons in the vicinity of the container. Thus, the probability of the shield being accidently or inadvertantly removed to gain access to the container, is greatly diminished.
It may be apparent that a novel and useful device for monitoring a container at the entrance structure has been hereinbefore described.
It is therefore an object of the present invention to provide a device for protecting an open container against trespass by living entities while the container is in a dangerous condition.
Another object of the present invention is to provide a device for monitoring a container entrance way which allows ventilation of gases to and from the container interior while preventing access to the interior of the container by unauthorized persons.
A further object of the present invention is to provide a device for monitoring a container having an entrance structure which is capable of supporting a probe of elongated shape, used to analyze the contents of the container.
Yet another object of the present invention is to provide a device for monitoring or preventing access to an open container, or tank, which is capable of fitting over the manway of the tank and adjusts to manways of different sizes and shapes.
The invention possesses other objects and advantages especially as concerns particular characteristics and features thereof which will become apparent as the specification continues.
Reference is now made to the following detailed description of the drawings which will aid the comprehension of the invention in the present application.